Bob ,there is only half an hour left for the coming train.

问题描述:

Bob ,there is only half an hour left for the coming train.
Hurry up,_______we‟ll miss the train.A.when B.and C.or D.then

答案选【C】,or这这里意为:否则
——鲍勃,只剩半个小时火车就要到站了.
——我们得赶快,【否则】就要错过这趟火车了.